Development and psychometric evaluation of a physician global assessment for type 2 systemic lupus erythematosus symptoms

Abstract

Objective Manifestations of SLE can be categorised as type 1 (classic signs and symptoms of SLE) or type 2 (fatigue, widespread pain and brain fog with an unclear relationship to inflammation). While measures of type 1 SLE activity exist, most current physician-reported measures do not encompass type 2 SLE manifestations. To better evaluate type 2 SLE symptoms, we developed and psychometrically evaluated a physician-reported measure of type 2 symptoms, the Type 2 Physician Global Assessment (‘Type 2 PGA’).Methods and analysis The Type 2 PGA was developed and evaluated by six rheumatologists practising in the same academic lupus clinic. The study began with a roundtable discussion to establish consensus guidelines for scoring the Type 2 PGA. Following the roundtable, the Type 2 PGA was psychometrically evaluated using data prospectively collected from 263 patients with SLE enrolled in the Duke Lupus Registry.Results There was strong intra-rater and inter-rater reliability (intraclass correlation coefficient=0.83), indicating the Type 2 PGA scores were consistent within a rheumatologist and across rheumatologists. The Type 2 PGA was correlated with patient-reported symptoms of polysymptomatic distress (r=0.76), fatigue (r=0.68), cognitive dysfunction (r=0.63), waking unrefreshed (r=0.62) and forgetfulness (r=0.60), and weakly correlated with the Type 1 PGA and the Systemic Lupus Erythematosus Disease Activity Index.Conclusion The Type 2 PGA performed well as a physician-reported measure of type 2 SLE symptoms. The incorporation of the Type 2 PGA into a routine rheumatology visit may improve patient care by bringing the provider’s attention to certain symptoms not well represented in conventional measures of disease activity.